SpotLocker Documentation / Helm, NMEA & Smartwatch

Helm Integration, NMEA 0183 & Wear OS Smartwatch

Connect SpotLocker to your vessel's Wi-Fi marine network, stream live depth sounder telemetry, and navigate from your wrist with Wear OS smartwatch integration.

1. NMEA 0183 Wi-Fi / UDP Network Streaming

SpotLocker features an integrated NMEA 0183 decoder service ([`nmea_service.dart`](file:///d:/prfndr/spotlocker/flutter_app/lib/services/nmea_service.dart)). By connecting your mobile phone or tablet to your boat's marine Wi-Fi gateway (e.g., Actisense, Digital Yacht, Quark-Elec, Yacht Devices, or Garmin/Lowrance Wi-Fi bridge), SpotLocker receives live sensor telemetry directly from your transducers.

Supported Standard NMEA Sentences

  • $SDDPT / $SDDDB — Water Depth Sounder reading in feet/meters.
  • $YXMTW — Water Surface Temperature in °F / °C.
  • $GPRMC / $GPGGA — High-precision GPS latitude, longitude, speed over ground (SOG), and true track heading (COG).
  • $HCHDG — Digital Magnetic Compass Heading.

Configuration Steps

1

Connect to Boat Wi-Fi Gateway

On your mobile device, connect to your boat's Wi-Fi access point (e.g., YachtNet_NMEA or DigitalYacht_1012).

2

Configure IP & Port in SpotLocker Settings

Open SpotLocker > Settings > NMEA Marine Network. Set Protocol to UDP or TCP, enter gateway IP (e.g., 192.168.1.1), and Port (default 10110 or 2000).

// Sample Raw NMEA 0183 Data Stream Ingested by NmeaService $GPRMC,123519,A,3459.184,N,07953.220,W,022.4,084.4,230326,003.1,W*6A $SDDPT,024.5,0.0*57 $YXMTW,068.5,F*1B

2. Wear OS Smartwatch Wrist Helm Display

Keep your hands free while steering the vessel or holding a rod. SpotLocker includes a standalone companion watch UI screen ([`wear_os_helm_screen.dart`](file:///d:/prfndr/spotlocker/flutter_app/lib/screens/wear_os_helm_screen.dart)) for Wear OS smartwatches.

SpotLocker Wear OS Smartwatch Helm Interface Mockup
Figure 3.0: Circular Wear OS Smartwatch Helm Screen showing compass ring, live boat speed (4.2 KTS), transducer depth (24.5 FT), and next waypoint distance pointer.

Watch Features

  • Heading Ring: High-contrast 360° digital compass ring displaying magnetic course.
  • Live Telemetry Dashboard: Large high-legibility readout for boat speed, water depth, and battery level.
  • Steer-To Waypoint Pointer: Dynamic arrow pointing directly toward your selected target waypoint with distance remaining in nautical miles or feet.

3. Nautical Audio Voice Announcement System

SpotLocker's Nautical Audio Service ([`nautical_audio_service.dart`](file:///d:/prfndr/spotlocker/flutter_app/lib/services/nautical_audio_service.dart)) provides hands-free text-to-speech voice announcements over Bluetooth boat speakers or headsets:

📢 Automated Voice Alerts
  • "Approaching Waypoint Brush Pile A — 100 feet remaining."
  • "Shallow water warning: Transducer depth 4.5 feet."
  • "Anchor drift detected — vessel moved 120 feet from anchor center."